15 No art is ever learned without a master. Even dumb animals and wild herds follow leaders of their own. Bees have princes, and cranes fly after one of their number in the shape of a Y. There is but one emperor and each province has but one judge. Rome was founded by two brothers, but, as it could not have two kings at once, was inaugurated by an act of fratricide. So too Esau and Jacob strove in Rebekah's womb. Each church has a single bishop, a single archpresbyter, a single archdeacon; and every ecclesiastical order is subjected to its own rulers.
A ship has but one pilot, a house but one master, and the largest army moves at the command of one man. That I may not tire you by heaping up instances, my drift is simply this. Do not rely on your own discretion, but live in a monastery. For there, while you will be under the control of one father, you will have many companions; and these will teach you, one humility, another patience, a third silence, and a fourth meekness. You will do as others wish; you will eat what you are told to eat; you will wear what clothes are given you; you will perform the task allotted to you; you will obey one whom you do not like, you will come to bed tired out; you will go to sleep on your feet and you will be forced to rise before you have had sufficient rest.
When your turn comes, you will recite the psalms, a task which requires not a well modulated voice but genuine emotion. The apostle says: “I will pray with the spirit and I will pray with the understanding also,” and to the Ephesians, “make melody in your hearts to the Lord.” For he had read the precept of the psalmist: “Sing ye praises with understanding.” You will serve the brothers, you will wash the guests' feet; if you suffer wrong you will bear it in silence; the superior of the community you will fear as a master and love as a father.
Whatever he may order you to do you will believe to be wholesome for you. You will not pass judgment upon those who are placed over you, for your duty will be to obey them and to do what you are told, according to the words spoken by Moses: “keep silence and hearken, O Israel.” You will have so many tasks to occupy you that you will have no time for [evil] thoughts; and while you pass from one thing to another and fresh work follows work done, you will only be able to think of what you have it in charge at the moment to do.
Source: Letters (New Advent)